Hi atom,

Among U.S-designed speaker brands, NHT, along with a few others, is one of the more neutral speakers, so it should make a reasonably good timbral match with the QS8s and M60s.

The contributions of the additional channels in a 7.1 system are fairly minimal--it kind of depends on the room and setup as well--so you should be okay.

Regards,

Alan Lofft,
Axiom Resident Expert (Retired)